J/AJ/157/49ivo://CDS.VizieR/J/AJ/157/49doi:10.26093/cds/vizier.51570049CDSPiatti A.E.Bailin J.2019-11-12T13:33:52Z2019-08-06T06:45:58ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frmagellanic-cloudsglobular-star-clustersgiant-starsvisible-astronomymedium-band-photometryWe report on the spread of [Fe/H] values in the massive Large Magellanic Cloud cluster NGC 1978, recently confirmed to harbor multiple populations of nearly the same age. We used accurate Stroemgren photometry of carefully selected cluster red giant branch stars along with a high-dispersion spectroscopy-based calibration of the metallicity-sensitive index m_1_. Once we accounted for the photometry quality, assessed from extensive artificial star tests to trace the photometric uncertainties as a function of the position of the cluster's center as well as the stellar brightness, and those from the metallicity calibration, we found that NGC 1978 exhibits a small metallicity spread of 0.035 dex (+/-0.019-0.023), depending on whether stars with individual {sigma}[Fe/H]=<0.15 dex or those located in the cluster's outer areas are considered. Such a spread in [Fe/H] is consistent with a cluster formation model with self-enrichment, if mass loss higher than 90% due to stellar evolutionary and galactic tidal effects is assumed. Nevertheless, scenarios in which the apparent [Fe/H] variation reflects CN abundance anomalies or less extreme mass-loss models with environmentally dependent self-enrichment should not be ruled out.2019AJ....157...49Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/157/49CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/136/375 : Chemical composition of LMC red giants (Mucciarelli+, 2008)J/AJ/142/48 : LMC star clusters structural parameters (Werchan+, 2011)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/157/49https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/157/49http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/157/49https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/157/49https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/157/49http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/157/49GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/157/49/table2 (Stroemgren photometry of stars in the field of NGC 1978)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/157/49/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/157/49/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/157/49/table2?GETtext/xml+votable180.050000true82.17968806-66.231201110.0055555555555555566/33113https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/157/49?format=asciiOpticaldefaultJ/AJ/157/49/table2Stroemgren photometry of stars in the field of NGC 1978e_Vmag[0.002/0.299] Uncertainty in Vmagmagstat.error;phot.mag;em.opt.VfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStar[1/1194] Star numbermeta.id;meta.mainintRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainr[2.8/169] Distance to the cluster centerarcsecpos.angDistancefloatVmag[14.952/22.146] Stroemgren V band magnitudemagphot.mag;em.opt.Bfloatb-y[0.103/1.9] Stroemgren b-y color indexmagphot.color;em.opt.B;em.opt.Vfloate_b-y[0.003/0.327] Uncertainty in b-ymagstat.error;phot.color;em.opt.Bfloatm1[-0.5/1.137] Stroemgren metallicity-sensitive index m_1_magphot.colorfloate_m1[0.006/0.611] Uncertainty in m1magstat.errorfloat